Compositions Comprising Xanthan Gum and Crystalline Alpha-1,3-Glucan

This application claims the benefit of U.S. Provisional Appl. No. 63/382,000 (filed Nov. 2, 2022), which is incorporated herein by reference in its entirety.

The present disclosure is in the field of polysaccharides. For example, the disclosure pertains to compositions comprising xanthan gum and crystalline alpha-1,3-glucan, and use of this material in various applications.

Driven by a desire to use polysaccharides in various applications, researchers have explored for polysaccharides that are biodegradable and that can be made economically from renewably sourced feedstocks. One such polysaccharide is alpha-1,3-glucan, an insoluble glucan polymer characterized by having alpha-1,3-glycosidic linkages. This polymer has been prepared, for example, using a glucosyltransferase enzyme isolated from(Simpson et al., Microbiology 141:1451-1460, 1995). Also for example, U.S. Pat. No. 7,000,000 disclosed the preparation of a spun fiber from enzymatically produced alpha-1,3-glucan. Various other glucan materials have also been studied for developing new or enhanced applications. For example, U.S. Patent Appl. Publ. No. 2015/0232819 discloses enzymatic synthesis of several insoluble glucans having mixed alpha-1,3 and -1,6 linkages.

New compositions comprising alpha-1,3-glucan are desired to enhance the economic value and performance characteristics of this material in various applications. Compositions are described herein comprising xanthan gum and crystalline alpha-1,3-glucan, for example, that address this need.

In one embodiment, the present disclosure concerns an aqueous composition comprising xanthan gum and insoluble alpha-glucan, wherein:

In another embodiment, the present disclosure concerns a method of producing an aqueous composition as presently disclosed, wherein the method comprises: blending together at least water, xanthan gum, and insoluble alpha-glucan herein.

The disclosures of all cited patent and non-patent literature are incorporated herein by reference in their entirety.

Unless otherwise disclosed, the terms “a” and “an” as used herein are intended to encompass one or more (i.e., at least one) of a referenced feature.

Where present, all ranges are inclusive and combinable, except as otherwise noted. For example, when a range of “1 to 5” (i.e., 1-5) is recited, the recited range should be construed as including ranges “1 to 4”, “1 to 3”, “1-2”, “1-2 & 4-5”, “1-3 & 5”, and the like. The numerical values of the various ranges in the present disclosure, unless expressly indicated otherwise, are stated as approximations as though the minimum and maximum values within the stated ranges were both proceeded by the word “about”. In this manner, slight variations above and below the stated ranges can typically be used to achieve substantially the same results as values within the ranges. Also, the disclosure of these ranges is intended as a continuous range including each and every value between the minimum and maximum values.

It is intended that every maximum numerical limitation given throughout this specification includes every lower numerical limitation, as if such lower numerical limitations were expressly written herein. Every minimum numerical limitation given throughout this specification will include every higher numerical limitation, as if such higher numerical limitations were expressly written herein. Every numerical range given throughout this specification will include every narrower numerical range that falls within such broader numerical range, as if such narrower numerical ranges were all expressly written herein.

It is to be appreciated that certain features of the present disclosure, which are, for clarity, described above and below in the context of aspects/embodiments, may also be provided in combination in a single element. Conversely, various features of the disclosure that are, for brevity, described in the context of a single aspect/embodiment, can also be provided separately or in any sub-combination.

The terms “alpha-glucan”, “alpha-glucan polymer” and the like are used interchangeably herein. An alpha-glucan is a polymer comprising glucose monomeric units linked together by alpha-glycosidic linkages. In typical aspects, the glycosidic linkages of an alpha-glucan herein are about, or at least about, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% alpha-glycosidic linkages. Examples of an alpha-glucan polymer herein include alpha-1,3-glucan.

The terms “alpha-1,3-glucan”, “poly alpha-1,3-glucan”, “alpha-1,3-glucan polymer” and the like are used interchangeably herein. Alpha-1,3-glucan is an alpha-glucan comprising glucose monomeric units linked together by glycosidic linkages, wherein at least about 50% of the glycosidic linkages are alpha-1,3. Alpha-1,3-glucan in some aspects comprises about, or at least about, 90%, 95%, or 100% alpha-1,3 glycosidic linkages. Most or all of the other linkages, if present, in alpha-1,3-glucan herein typically are alpha-1,6, though some linkages may also be alpha-1,2 and/or alpha-1,4. Alpha-1,3-glucan herein is typically water-insoluble.

The terms “xanthan gum”, “xanthan”, “xanthan polysaccharide” and like terms herein refer to a water-soluble polysaccharide that typically is produced bybacteria (e.g.,), such as in an industrial fermentation. Xanthan gum can be as disclosed in, for example,(A. M. Grumezescu and A. M. Holban, Ed., Chapter 4, N. Jindal and J. S. Khattar, Microbial Polysaccharides in Food Industry, Academic Press, 2018) or U.S. Patent Appl. Publ. No. 2003/0143179, which are incorporated herein by reference.

The terms “linkage”, “glycosidic linkage”, “glycosidic bond” and the like refer to the covalent bonds connecting the sugar monomers within a saccharide compound (oligosaccharides and/or polysaccharides). Examples of glycosidic linkages include 1,6-alpha-D-glycosidic linkages (herein also referred to as “alpha-1,6” linkages) and 1,3-alpha-D-glycosidic linkages (herein also referred to as “alpha-1,3” linkages).

The glycosidic linkage profile of a polysaccharide can be determined using any method known in the art. For example, a linkage profile can be determined using methods using nuclear magnetic resonance (NMR) spectroscopy (e.g.,C NMR and/orH NMR). These and other methods that can be used are disclosed in, for example,(S. W. Cui, Ed., Chapter 3, S. W. Cui, Structural Analysis of Polysaccharides, Taylor & Francis Group LLC, Boca Raton, FL, 2005), which is incorporated herein by reference.

The “molecular weight” of a polysaccharide herein such as an alpha-glucan can be represented as weight-average molecular weight (Mw) or number-average molecular weight (Mn), the units of which are in Daltons (Da) or grams/mole. Alternatively, molecular weight can be represented as DPw (weight average degree of polymerization) or DPn (number average degree of polymerization). The molecular weight of smaller polysaccharide polymers such as oligosaccharides can optionally be provided as “DP” (degree of polymerization), which simply refers to the number of monomers comprised within the polysaccharide; “DP” can also characterize the molecular weight of a polymer on an individual molecule basis. Various means are known in the art for calculating these various molecular weight measurements such as with high-pressure liquid chromatography (HPLC), size exclusion chromatography (SEC), or gel permeation chromatography (GPC).

As used herein, Mw can be calculated as Mw=ΣNiMi/ΣNiMi; where Mi is the molecular weight of an individual chain i and Ni is the number of chains of that molecular weight. Besides SEC, the Mw of a polymer can be determined by other techniques such as static light scattering, mass spectrometry, MALDI-TOF (matrix-assisted laser desorption/ionization time-of-flight), small angle X-ray or neutron scattering, or ultracentrifugation. As used herein, Mn can be calculated as Mn=ΣNiMi/ΣNi where Mi is the molecular weight of a chain i and Ni is the number of chains of that molecular weight. Besides SEC, the Mn of a polymer can be determined by various colligative property methods such as vapor pressure osmometry, end-group determination by spectroscopic methods such as proton NMR, proton FTIR, or UV-Vis. As used herein, DPn and DPw can be calculated from Mn and Mw, respectively, by dividing them by molar mass of the one monomer unit Mi. In the case of unsubstituted glucan polymer, M=162. In the case of a substituted (derivatized) glucan polymer, M=162+M×DoS, where Mis molar mass of the substituting group, and DoS is degree of substitution (average number of substituted groups per one glucose unit of the glucan polymer).

The terms “crystalline”, “crystalline solid”, “crystal” and like terms herein refer to a solid material whose constituents are arranged in a regularly ordered structure forming a lattice; such material typically is a portion of a larger composition having both crystalline and amorphous regions. An “amorphous” material is non-crystalline in that its constituents are not organized in a definite lattice pattern, but rather are randomly organized. Crystalline materials, but not amorphous materials, usually have a characteristic geometric shape (e.g., plate). The terms “crystallinity”, “crystallinity index” (CI), “degree of crystallinity” and the like herein refer to the fractional amount (mass fraction or volume fraction) of an insoluble alpha-glucan that is crystalline, and can be referred to in decimal or percentage form (e.g., a crystallinity of 0.65 corresponds to a crystallinity of 65%). This fractional amount is of a total amount or volume that includes the amorphous content of the insoluble alpha-glucan. Crystallinity herein can be as measured using techniques such as differential scanning calorimetry (DSC), X-ray diffraction (XRD), small angle X-ray scattering (SAXS), infrared spectroscopy, and/or density measurements according to, for example, Struszczyk et al. (198733:177-189), U.S. Patent Appl. Publ. Nos. 2015/0247176, 2010/0233773, 2015/0152196, 2020/0181370, or 2021/0130504, which are all incorporated herein by reference. In some aspects, the crystallinity of insoluble alpha-glucan herein can be as determined according to the methodology disclosed in the below Examples (Materials/Methods).

The terms “particle”, “particulate” and like terms are interchangeably used herein, and refers to the smallest identifiable unit in a particulate system. The term “particulated” and like terms can be used to characterize particles of insoluble alpha-glucan herein; particulated insoluble alpha-glucan in typical aspects of the present disclosure is as this material exists when dispersed under aqueous conditions. Particle size in some aspects can refer to particle diameter and/or the length of the longest particle dimension. The average size can be based on the average of diameters and/or longest particle dimensions of at least 50, 100, 500, 1000, 2500, 5000, or 10000 or more particles, for example. Particles herein can be in plate form, for instance. Particle size herein can be measured by a process comprising light scattering or electrical impedance change (e.g., using a Coulter Counter), for example, such as described in any of U.S. Pat. Nos. 6,091,492, 6,741,350, or 9297737 (each incorporated herein by reference). Particle size and/or distributions can be as measured for particles comprised in an aqueous dispersion, for example. Particle size herein can optionally be expressed by a “D”, “D”, “D”, etc. value; for example, a Dvalue is the diameter for which 50% by weight of the particles in a composition (e.g., dispersion) have a diameter under that diameter, and 50% by weight of the particles have a diameter greater than that diameter.

The terms “plate”, “platy”, “plate-like”, “flakey” and like terms herein characterize the shape of insoluble alpha-glucan particles in some aspects. Particles having this shape herein generally are flat (more two-dimensional than three-dimensional), as opposed to being spherical, cylindrical, fibrillar, fibrous, rod-like, cubic, acicular, spongey/porous, lamellar, or of some other shape. Particles herein can optionally be referred to as “plates”, “platelets”, and like terms, and/or collectively as “microcrystalline glucan” (MCG) and like terms.

A composition herein that is “dry” or “dried” typically has less than 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0.5, or 0.1 wt % water comprised therein.

The terms “aqueous liquid”, “aqueous fluid”, “aqueous conditions”, “aqueous reaction conditions”, “aqueous setting”, “aqueous system” and the like as used herein can refer to water or an aqueous solution. An “aqueous solution” herein can comprise one or more dissolved salts, where the maximal total salt concentration can be about 3.5 wt % in some aspects. Although aqueous liquids herein typically comprise water as the only solvent in the liquid, an aqueous liquid can optionally comprise one or more other solvents (e.g., polar organic solvent) that are miscible in water. Thus, an aqueous solution can comprise a solvent having at least about 10 wt % water.

An “aqueous composition” herein has a liquid component that comprises about, or at least about, 10, 20, 30, 40, 50, 60, 70, 80, 90, 95, 99, or 100 wt % water, for example. Examples of aqueous compositions include mixtures, solutions, dispersions (e.g., colloidal dispersions), suspensions and emulsions, for example.

As used herein, the term “colloidal dispersion” refers to a heterogeneous system having a dispersed phase and a dispersion medium, i.e., microscopically dispersed insoluble particles are suspended throughout another substance (e.g., an aqueous composition such as water or aqueous solution). An example of a colloidal dispersion herein is a hydrocolloid. All, or a portion of, the particles of a colloidal dispersion such as a hydrocolloid can comprise insoluble alpha-glucan as presently disclosed. The terms “dispersant” and “dispersion agent” are used interchangeably herein to refer to a material that promotes the formation and/or stabilization of a dispersion. “Dispersing” herein refers to the act of preparing a dispersion of a material in an aqueous liquid. As used herein, the term “latex” (and like terms) refers to a dispersion of one or more types of polymer particles in water or aqueous solution; typically, at least particles herein are in a latex composition as a dispersed polymer component. In some aspects, a latex is an emulsion that comprises a dispersion of at least particles herein. An “emulsion” herein is a dispersion of minute droplets of one liquid in another liquid in which the droplets are not soluble or miscible (e.g., a non-polar substance such as oil or other organic liquid such as an alkane, in a polar liquid such as water or aqueous solution). An emulsion can further comprise dispersed alpha-glucan herein, for example, which optionally can stabilize the emulsion. In some aspects, however, an emulsion herein can be a “dry emulsion”. A dry emulsion is typically produced by removing all or most (e.g. >95%, >99%, or >99.5%) of the water of a liquid emulsion, such as by freeze-drying or spray-drying.

Compositions of the present disclosure can provide stability to a dispersion or emulsion, for example. The “stability” (or the quality of being “stable”) of a dispersion or emulsion herein is, for example, the ability of dispersed particles of a dispersion, or liquid droplets dispersed in another liquid (emulsion), to remain dispersed (e.g., about, or at least about, 70, 75, 80, 85, 90, 95, 96, 97, 98, 99, or 100 wt % of the particles of the dispersion or liquid droplets of the emulsion are in a dispersed state) for a period of about, or at least about, 2, 4, 6, 9, 12, 18, 24, 30, or 36 months following initial preparation of the dispersion or emulsion. A stable dispersion or emulsion in some aspects can resist total sedimentation, flocculation, and/or coalescence of dispersed/emulsified material.

An alpha-glucan that is “insoluble”, “aqueous-insoluble”, “water-insoluble” (and like terms) (e.g., alpha-1,3-glucan with a DP of 8 or higher) herein does not dissolve (or does not appreciably dissolve) in water or other aqueous conditions, optionally where the aqueous conditions are further characterized to have a pH of 4-9 (e.g., pH 6-8) and/or temperature of about 1 to 130° C. (e.g., 20-25° C.). In some aspects, less than 1.0 gram (e.g., no detectable amount) of an aqueous-insoluble alpha-glucan herein dissolves in 1000 milliliters of such aqueous conditions (e.g., water at 23° C.). In contrast, glucans such as certain oligosaccharides herein that are “soluble”, “aqueous-soluble”, “water-soluble” and the like (e.g., alpha-1,3-glucan with a DP less than 8) appreciably dissolve under these conditions.

The term “viscosity” as used herein refers to the measure of the extent to which a fluid (aqueous or non-aqueous) resists a force tending to cause it to flow. Various units of viscosity that can be used herein include centipoise (cP, cps) and Pascal-second (Pa-s), for example. A centipoise is one one-hundredth of a poise; one poise is equal to 0.100 kg·m·s.

The terms “household care product”, “home care product”, and like terms typically refer to products, goods and services relating to the treatment, cleaning, caring, and/or conditioning of a home and its contents. The foregoing includes, for example, chemicals, compositions, products, or combinations thereof having application in such care.

A “fabric care composition”, “laundry care composition”, and like terms refer to any composition suitable for treating fabric, non-wovens, and/or any similar material in some manner. Examples of such a composition include laundry detergents and fabric softeners.

A “detergent composition” herein typically comprises at least a surfactant (detergent compound) and/or a builder. A “surfactant” herein refers to a substance that tends to reduce the surface tension of a liquid in which the substance is dissolved. A surfactant may act as a detergent, wetting agent, emulsifier, foaming agent, and/or dispersant, for example.

The term “personal care product” and like terms typically refer to products, goods and services relating to the treatment, cleaning, cleansing, caring or conditioning of a person. The foregoing include, for example, chemicals, compositions, products, or combinations thereof having application in such care.

The term “medical product” and like terms typically refer to products, goods and services relating to the diagnosis, treatment, and/or care of patients.

The term “industrial product” and like terms typically refer to products, goods and services used in industrial or institutional settings, but typically not by individual consumers.

The terms “ingestible product”, “ingestible composition” and the like refer to any substance that, either alone or together with another substance, may be taken orally (i.e., by mouth), whether intended for consumption or not. Thus, an ingestible product includes food/beverage products. “Food/beverage products” refer to any edible product intended for consumption (e.g., for nutritional purposes) by humans or animals, including solids, semi-solids, or liquids. A “food” herein can optionally be referred to as a “foodstuff”, “food product”, or other like term, for example. “Non-edible products” (“non-edible compositions”) refer to any composition that can be taken by the mouth for purposes other than food or beverage consumption. Examples of non-edible products herein include supplements, nutraceuticals, functional food products, pharmaceutical products, oral care products (e.g., dentifrices, mouthwashes), and cosmetic products such as sweetened lip balms. A “pharmaceutical product”, “medicine”, “medication”, “drug” or like term herein refers to a composition used to treat disease or injury, and can be administered enterally or parenterally.

The terms “percent by volume”, “volume percent”, “vol %”, “v/v %” and the like are used interchangeably herein. The percent by volume of a solute in a solution can be determined using the formula: [(volume of solute)/(volume of solution)]×100%.

The terms “percent by weight”, “weight percentage (wt %)”, “weight-weight percentage (% w/w)” and the like are used interchangeably herein. Percent by weight refers to the percentage of a material on a mass basis as it is comprised in a composition, mixture, or solution.

The terms “weight/volume percent”, “w/v %” and the like are used interchangeably herein. Weight/volume percent can be calculated as: ((mass [g] of material)/(total volume [mL] of the material plus the liquid in which the material is placed))×100%. The material can be insoluble in the liquid (i.e., be a solid phase in a liquid phase, such as with a dispersion), or soluble in the liquid (i.e., be a solute dissolved in the liquid).

The term “isolated” means a substance (or process) in a form or environment that does not occur in nature. A non-limiting example of an isolated substance includes any aqueous alpha-glucan composition disclosed herein (e.g., further comprising xanthan gum). It is believed that the embodiments disclosed herein are synthetic/man-made (could not have been made or practiced except for human intervention/involvement), and/or have properties that are not naturally occurring.

The term “increased” as used herein can refer to a quantity or activity that is at least about 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 50%, 100%, or 200% more than the quantity or activity for which the increased quantity or activity is being compared. The terms “increased”, “elevated”, “enhanced”, “greater than”, “improved” and the like are used interchangeably herein.

Some aspects of the present disclosure concern an aqueous composition (product) comprising xanthan gum and insoluble alpha-glucan, wherein:

Such compositions as presently disclosed have several advantageous features. For example, aqueous compositions herein can exhibit synergistic enhancement of viscosity. Also for example, aqueous compositions herein can exhibit enhanced stability.

An aqueous composition of the present disclosure comprises insoluble alpha-glucan, wherein at least about 50% of the glycosidic linkages of the insoluble alpha-glucan are alpha-1,3 glycosidic linkages. In some aspects, about, or at least about, 50%, 60%, 70%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 99.5%, or 100% of the glycosidic linkages of insoluble alpha-glucan are alpha-1,3 glycosidic linkages. Typically, the glycosidic linkages that are not alpha-1,3 are mostly or entirely alpha-1,6. It should be understood that the higher the percentage of alpha-1,3 linkages present in an insoluble alpha-glucan, the greater the probability that the glucan is linear, since there are lower occurrences of certain linkages that might be part of branch points. In some aspects, insoluble alpha-glucan has no branch points or less than about 5%, 4%, 3%, 2%, or 1% branch points as a percent of the glycosidic linkages in the alpha-glucan.

In some aspects, the DPw, DPn, or DP of insoluble alpha-glucan can be about, at least about, or less than about, 10, 15, 20, 25, 30, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 65, 70, 75, 80, 85, 90, 95, 100, 110, 125, 150, 175, 200, 15-100, 25-100, 35-100, 15-80, 25-80, 35-80, 15-60, 25-60, 35-60, 15-55, 25-55, 25-50, 35-55, 35-50, 35-45, 35-40, 40-100, 40-80, 40-60, 40-55, 40-50, 45-60, 45-55, or 45-50.

An aqueous composition of the present disclosure can, in some aspects, comprise insoluble alpha-glucan that is in the form of particles having a degree of crystallinity of at least about 0.65. The degree of crystallinity (or crystallinity index [CI]) of insoluble alpha-glucan particles herein can be about, or at least about, 0.55, 0.60, 0.65, 0.66, 0.67, 0.68, 0.69, 0.70, 0.71, 0.72, 0.73, 0.74, 0.75, 0.76, 0.77, 0.78, 0.79, 0.80, 0.81, 0.82, 0.83, 0.84, 0.85, 0.60-0.83, 0.65-0.83, 0.67-0.83, 0.69-0.83, 0.60-0.81, 0.65-0.81, 0.67-0.81, 0.69-0.81, 0.60-0.78, 0.65-0.78, 0.67-0.78, 0.69-0.78, 0.60-0.76, 0.65-0.76, 0.67-0.76, or 0.69-0.76, for example. In general, that portion of insoluble alpha-glucan herein that is not crystalline is amorphous. Flowing from the foregoing crystallinity values, the wt % of particles that is amorphous is about, or less than about, 45%, 40%, 35%, 30%, 25%, 20%, or 15%, for example. The degree of crystallinity of alpha-glucan particles herein can be as when measured according to any suitable method, such as follows. A sample of insoluble alpha-glucan herein is dried for at least about 2 hours (e.g., 8-12 hours) in a vacuum oven set at about 55-65° C. (e.g., 60° C.). The sample is then be packed into a stainless steel holder with a well of about 1-2 cm wide by 3-5 cm long by 3-5 mm deep, after which the holder is loaded into a suitable diffractometer (e.g., X'PERT MPD POWDER diffractometer, PANalytical B.V., The Netherlands) set in reflection mode to measure the X-ray diffraction pattern of the sample. The X-ray source is a Cu X-ray tube line source with an optical focusing mirror and a ˜ 1/16° narrowing slit. X-rays are detected with a 1-D detector and an anti-scatter slit set at ˜⅛°. Data are collected in the range of about 4 to 60 degrees of two-theta at about 0.1 degrees per step. The resulting X-ray pattern is then analyzed by subtracting a linear baseline from about 7.2 to 30.5 degrees, subtracting the XRD pattern of a known amorphous alpha-1,3-glucan sample that has been scaled to fit the data, and then fitting the remaining crystal peaks in that range with a series of Gaussian curves corresponding to known dehydrated alpha-1,3-glucan crystal reflections. The area corresponding to the crystal peaks is then divided by the total area under the baseline-subtracted curve to yield a crystallinity index.

At least about 80 wt % of particles of insoluble alpha-glucan having any of the foregoing degrees of crystallinity can be in the form of plates, for example. In some aspects, about, or at least about, 60, 65, 70, 75, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 60-85, 60-80, 60-75, 60-70, 65-85, 65-80, 65-75, 65-70, 70-85, 70-80, or 70-75 wt % of the particles of insoluble alpha-glucan are in the form of plates. Plates of insoluble alpha-glucan herein can be visually appreciated when viewed by electron microscopy such as TEM or SEM, for example. Typically, the balance of particles of insoluble alpha-glucan are of non-plate form. In some aspects, the balance of the particles that are of non-plate form can be characterized as being fibrillar and/or striated in appearance. However, in some aspects, about, or at least about, 10, 20, 30, 40, 50, 60, or 70 wt % of the particles of insoluble alpha-glucan in a composition herein are in the form of plates.

In some aspects, at least about 65% by weight of insoluble alpha-glucan particles having any of the foregoing degrees of crystallinity have a diameter of less than 1.0 micron. Yet, in some aspects, about, or at least about, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 65-95%, 70-95%, 75-95%, 80-95%, 85-95%, 65-90%, 70-90%, 75-90%, 80-90%, 85-90%, 65-85%, 70-85%, 75-85%, or 80-85% by weight of insoluble alpha-glucan particles have a diameter of less than about 1.0 micron. In some aspects, about 40-60%, 40-55%, 45-60%, 45-55%, 47-53%, 48-52%, 49-51%, or 50% by weight of the insoluble alpha-glucan particles have a diameter of about, or less than about, 1.0, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.35, 0.34, 0.32, 0.30, 0.28, 0.26, 0.25, 0.24, 0.23, 0.22, 0.21, 0.20, 0.19, 0.18, 0.17, 0.16, 0.15, 0.14, 0.13, 0.12, 0.11, 0.10, 0.10-1.0, 0.10-0.80, 0.10-0.60, 0.10-0.40, 0.10-0.35, 0.10-0.30, 0.10-0.25, 0.10-0.20, 0.15-0.35, 0.15-0.30, 0.15-0.25, or 0.15-0.20 micron. In some aspects, about 40-60%, 40-55%, 45-60%, 45-55%, 47-53%, 48-52%, 49-51%, or 50% by weight of insoluble alpha-glucan particles are aggregates of the foregoing smaller diameter particles, and have a diameter of about, less than about, or at least about, 10, 25, 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 10-600, 10-550, 10-500, 50-600, 50-550, 50-500, 100-600, 100-550, 100-500, 150-600, 150-550, 150-500, 200-600, 200-550, 200-500, 250-600, 250-550, or 250-500 microns. Alpha-glucan particles having any of the foregoing degrees of crystallinity can have a thickness of about 0.010, 0.015, 0.020, 0.025, 0.030, or 0.010-0.030 micron, for example; such a thickness can optionally be in conjunction with any of the foregoing diameter aspects. The foregoing particle size and/or distributions for crystalline particles herein can be as measured for particles comprised in an aqueous dispersion, and/or as measured using a light scatter technique, for example.

Insoluble alpha-glucan can be in the form of particles in some aspects. As comprised in an aqueous composition herein such as a dispersion or emulsion, about 40-60%, 40-55%, 45-60%, 45-55%, 47-53%, 48-52%, 49-51%, or 50% by weight of insoluble alpha-glucan particles herein can have a diameter (i.e., D) of about, less than about, or at least about, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 1-25, 1-22, 1-20, 1-18, 5-25, 5-22, 5-20, 5-18, 15-22, 15-20, 15-18, 16-22, 16-20, or 16-18 microns, for example.

Insoluble alpha-glucan in the form of particles having a degree of crystallinity of at least about 0.65 can be produced, for example, by a method comprising the following steps: (a) providing insoluble alpha-glucan (precursor) as produced in an enzymatic reaction comprising at least water, sucrose and a glucosyltransferase enzyme that synthesizes the insoluble alpha-glucan, wherein the insoluble alpha-glucan has a DPw or DPn of at least about, or over about, 100, 150, or 200, and at least 50% of its glycosidic linkages are alpha-1,3 glycosidic linkages; (b) hydrolyzing the insoluble alpha-glucan (precursor) to insoluble alpha-glucan particles with a DPw or DPn, for example, of about 10 to 100 (e.g., any DPw or DPn value herein falling in this range), wherein the hydrolyzing is performed under aqueous conditions at a pH of 2.0 or less, and (c) optionally isolating the insoluble alpha-glucan particles produced in step (b). Step (b) of this method can optionally be characterized as an “acid hydrolysis” method or reaction. Insoluble alpha-glucan precursor herein for entry into acid hydrolysis is itself insoluble alpha-glucan, but has a molecular weight that is greater than that of the insoluble alpha-glucan produced by the hydrolysis method. An insoluble alpha-glucan precursor can have a glycosidic linkage profile as disclosed above (e.g., at least about 50%, 60%, 70%, 80%, 90%, 95%, 99%, 99.5%, or 100% alpha-1,3 glycosidic linkages) and a DPw or DPn of about, at least about, or over about, 200 (e.g., any such DPw or DPn as disclosed above).

Insoluble alpha-glucan herein can be as disclosed (e.g., molecular weight, linkage profile, crystallinity, and/or production method), for example, in U.S. Pat. Nos. 7,000,000, 8,871,474, 10,301,604, or 10,260,053, or U.S. Patent Appl. Publ. Nos. 2019/0112456, 2019/0078062, 2019/0078063, 2018/0340199, 2018/0021238, 2018/0273731, 2017/0002335, 2015/0232819, 2015/0064748, 2020/0165360, 2020/0131281, 2019/0185893, 2019/0276806, or 2021/0130504, which are each incorporated herein by reference. Insoluble alpha-glucan can be produced, for example, by an enzymatic reaction comprising at least water, sucrose and a glucosyltransferase enzyme that synthesizes the insoluble alpha-glucan. Glucosyltransferases, reaction conditions, and/or processes contemplated to be useful for producing insoluble alpha-glucan can be as disclosed in any of the foregoing references.